The present exemplary embodiment relates generally to a fusing system for fusing marked media and more particularly to a fuser member with a reinforced slot for accepting a drive gear.
Fuser rolls used in electrographic imaging systems generally comprise a metal core cylinder coated with one or more elastomer layers. The fuser roll is heated, either internally or externally, to provide a heated exterior surface for fusing marking materials, such as toners, to paper or other marking media. Conventional fuser roll core cylinders are relatively thick-walled aluminum alloy cylinders. The thickness has been employed in order to provide strength and durability as the fuser roll presses against the adjacent compression roll in the nip region.
Typically, the fuser roll is allowed to cool between fusing operations to conserve energy and prolong the life of the fuser roll. The warm-up time of a fuser roll depends on its mass. It is desirable for the fuser roll to reach an operating temperature of about 150–200° C. within a relatively short period of time using conventional power sources. In order to save energy and shorten warm-up times, the fuser roll wall thickness has been progressively reduced. However, it has been found that the thinner cylinder walls are subject to weakness and cracking, particularly in the end region of the cylinder where a drive slot is punched out of the fuser core cylinder. The drive slot receives a key of a drive gear for rotation of the core cylinder. As the fuser roll rotates, the pressure placed on the fuser roll at the nip tends to cause the fuser roll to be slightly out of round. The slot acts as a stress raiser. Cracks may propagate from the slot, ultimately causing the failure of the fuser roll.
Various attempts have been made to strengthen the slot. In one method, a rib is mounted to the fuser roll in the region of the slot.